Hypothesis testing for mean and proportion.

1. A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors was selected. assume you reject the null hypothesis. What conclusion can you draw?
i)There is not sufficient evidence that proportion of doctors who recommend aspirin is not less than 0.90.
ii)There is sufficient evidence that proportion of doctors who recommend aspirin is not less than 0.90.
iii)There is not sufficient evidence that proportion of doctors who recommend aspirin is less than 0.90.
iv)There is sufficient evidence that proportion of doctors who recommend aspirin is less than 0.90.

2. A major videocassette rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with videocassette recorders (VCRs). It conducts a telephone poll of 300 at random selected households in the area and finds that 96 have VCRs. status the test of interest to the rental chain.

3. A major videocassette rental chain is considering opening a new store in an area that currently does not have any such stores. The chain would open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with videocassette recorders (VCRs). It conducts a telephone poll of 300 randomly particular households in the area and finds that 96 have VCRs. The value of the test statistic in this problem is approximately equal to:
a)2.80
b)2.60
c)1.94
d)1.30

4. A major videocassette rental chain is considering opening a new store in an area that currently does not have any such stores. The chain would open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with videocassette recorders (VCRs). It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have VCRs. The p-value associated with the test statistic in this problem is approximately equal to:

a) 0.0100
b) 0.0051
c) 0.0026
d) 0.0013

5. An appliance manufacturer claims to have developed a compact microwave oven that consumes an average of no more than 250 W. From previous studies, it is believed that power consumption for microwave ovens is normally distributed with a standard deviation of 15 W. A consumer group has decided to try to discover if the claim appears true. They take a sample of 20 microwave ovens and find that they consume an average of 257.3 W.